1/4" male mono plug to RCA Right angle adapter, gold plated.
RCA right angle female to 1/4" male adapter, lets you convert an RCA connector to a 1/4" plug in a limited space. Very high quality for critical audio...

3.5mm female stereo mini plug to 1/4" male stereo phone plug.
Plug a small portable electronics style headset into a large headphone jack such as on a Receiver, Home theater system or boom box.
Stereo 3...

3.5mm female stereo mini phone jack to 1/4" male right angle stereo phone plug adapter.
iPods, iPhones, and most new small Audio/Video devices use the small 3.5mm (1/8") Jack for headphones to save space...